we introduce variational inequality problems on hilbert $c^*$-modules and we prove several existence results for variational inequalities defined on closed convex sets. then relation between variational inequalities, $c^*$-valued metric projection and fixed point theory  on  hilbert $c^*$-modules is studied.

Azam et al. (2011), introduce the notion of complex valued metric spaces and obtained common fixed point result for mappings in the context of complex valued metric spaces. Rao et al. (2013) introduce the notion of complex valued b-metric spaces. In this paper, we generalize the results of Azam et al. (2011), and Bhatt et al. (2011), by improving the conditions of contraction to establish the e...

Abbas M, Arsad M, Azam A (2013), Fixed points of asymptotically regular mappings in complex-valued metric spaces, Georgian Math. J. , 20 (2), 213-221. Abbas M. Fisher B, Nazir T (2012), Well-posedness and periodic point property of mappings satisfying a rational inequality in an ordered complex valued metric space, Sci. Stud. Res. , Ser. Math. Inform. , 22 (1), 5-24. Ahmad J, Klin-Eam C, Azam A...

Abbas M, Arsad M, Azam A (2013), Fixed points of asymptotically regular mappings in complex-valued metric spaces, Georgian Math. J. , 20 (2), 213-221. Abbas M. Fisher B, Nazir T (2012), Well-posedness and periodic point property of mappings satisfying a rational inequality in an ordered complex valued metric space, Sci. Stud. Res. , Ser. Math. Inform. , 22 (1), 5-24. Ahmad J, Klin-Eam C, Azam A...